H5N1 H5N1 Virus Human Health Risks Bird Flu Human Cases A(H5N1) Impact on Animals Vaccines Highly Pathogenic Avian Influenza H7N9 Human Health Impact H5N1 Bird Flu Symptoms H3N8 Strain H5 Subtype Public Health Highly Pathogenic Bird Flu Transmission Zoonotic Diseases Transmission to Humans
Health officials warn the mutated avian flu strain poses serious health threats.